Switch having variable differential and range adjustment



Oct. 20, 1964 C. F. WEISGERBER Original Filed July .20. 1959 FIG. 1.

2 Sheets-Sheet 1 Fla. 4-. z 5

A x I I. v )I J; 9\ /2 I l w 35' INVENTOR. G- CHARLES Fwsazug-R anvr 20,1964 c. F. WEISGERBER 3,153,715

SWITCH HAVING VARIABLE DIFFERENTIAL AND RANGE ADJUSTMENT Original FiledJuly 20, 1959 2 Sheets-Sheet 2 INVENTOR. CHARLES .E WEI-SGERBER UnitedStates Patent Ofiice 3,153,715 Patented Oct. 20, 1964 3,153,715 SWITCHHAVING VARIABLE DIFFERENTIAL AND RANGE ADJUSTMENT Charles F. Weisgerber,Whittier, Calif.

'(P.O. Box 1489, Wickenburg, Ariz.) Continuation of application Ser. No.828,131, July 20, 1959. This application July 30, 1962, Ser. No. 213,5277 Claims. (Cl. 200-170) This invention relates to a switch havingvariable differential and range and is particularly concerned with thecontrol of an electrical circuit, or the like, by means of fluidpressures and throughout wide variables in both ditierential and rangepressures and whereby accurate sensing of certain determined fluidpressures is usable to operate other devices as circumstances require,it being a general object of this invention to provide a practical andreliable switch that can be manually adjusted and which is accurate inthe sensing, for example, of fiuid pressures to which it is responsive.

This application is filed as a continuation of applica tion Serial No.828,131 filed July 20, 1959, and now abandoned.

Fluid operated pressure control switches of the type under considerationhave been used for numerous purposes and where it is desired to governthe action of other devices in response to a fluid pressure. Theordinary control switches in which incremental movements are achievedare characterized by bellows or cylinder and piston actuated mechanicallinkages, said linkages being multiplying lever-type linkages. Thecommon linkage in such control switches, such as the multiplying leversthereof, are not only costly but they become inoperative for practicalpurposes in a very short time due to wear and play in the multiplicityof parts involved. In other words, when wear occurs where a multiplicityof parts is involved in a mechanism of the type under consideration, asin a usual multiplying linkage, there is a build-up of error and/or amagnification thereof and to such an extent as to render the controlswitch practically inoperative and useless.

An object of this invention is to provide a switch that is direct in itsmovement and wherein play or movements resulting from inaccuracies orfrom wear are not detrimental to the accuracy thereof. With the switchthat I provide both differential and range pressures are adjustablyvariable and incorporated in a mechanism characterized by straightlineal movement involving a minimum number of parts.

It is an object of this invention to provide a pressure operated switchthat is'responsive to both high and low fluid pressures wherein therange of said high and low fluid pressures is adjustably set as desiredand at any time either before or after or during operation of theswitch.

It is also object of this invention to provide a pressure operatedswitch that is responsive to both high and low fluid pressures andwherein the differential of said high and low fluid pressures isadjustably set as desired and at any time either before or after orduring operation of the switch.

Further, it is an object of this invention to provide a pressureoperated switch that is independently responsive to both adjustablyselected differential and range settings, as above referred to, andwherein each of said differential and range settings can beindependently eflected without disturbing or affecting either one or theother.

Also, it is an object of this invention to provide a pressure operatedswitch of the character referred to that is infinitely variable andinfinitely responsive, within its operational range, to bothdiflerential and range settings and pressures, respectively.

An object of this invention is to provide a relatively simple and ruggedcontrol switch having the features thus far referred to and which isalso inexpensive of manufacture and inherently long lived.

The various objects and features of my invention will be fullyunderstood from the following detailed description thereof, throughoutwhich description reference is made to the accompanying drawings, inwhich:

FIG. 1 is a side elevation of a pressure operated switch involving theembodiments of the present invention. FIG. 2 is a front elevation of theswitch shown in FIG. 1 and taken as indicated by line 22 on FIG. 1. FIG.3 is an enlarged detailed longitudinal sectional view takensubstantially as indicated by line 3-3 on FIG. 2. FIG. 4 is a transversesectional view taken as indicated by line 44 on FIG. 3, and FIG. 5 is adetailed sectional view of a portion of the switch and taken asindicated by line 5-5 on FIG. 4.

The control switch of the present invention is preferably an electricalcontrol switch involving two or more spaced contacts that are movablyand adjustably related to each other. The switch is fluid operated orresponsive to fluid under pressure, either gas or liquid, and isoperated by fluctuations in said fluid pressures. It will be apparentthat the means responsive to pressure of fluid and adapted to shift amovable element can vary widely and, therefore, it is contemplated thatany suitable means, such as, for example, a cylinder and piston unit, ora Bourdon tube can be employed as desired. It is to be understood,however, and in accordance with the broader principles of the presentinvention, that when I refer to pressure I not only mean fluid or liquidor gas pressure, but I also mean to include any and all other pressuresincluding mechanical and electrical pressures. Therefore, the meansresponsive to pressure can be in the form of a mechanical bi-metallicthermostat mechanism or the like, or it can be in the form of anelectrical or voltage 0perated mechanism or the like. Further, it is tobe understood that the switch can be other than an electrical switch,such as, for example, a mechanical tripping device or sear, or, forexample, a hydraulic latching device.

In FIGS. 1 and 2 of the drawings I have illustrated a typical embodimentof the control switch and which is diaphragm operated by fluid pressureto open and close an electrical circuit or circuits. A control switch,such as illustrated, can be employed, for example, for the control ofgases or air, as in a furnace exhaust, or for missing and/or control ofair of various percentages, or of various temperatures and densities, orsimply for the control of gas or liquid pressures in a flow line, or forcontrolling any electrical circuit, as circumstances require. As shown,the switch X is cooperatively related to a pressure responsive means Ythat is coupled to a pressure supply Z. The particular switch Xillustrated is an electrical switch involving a plurality of contacts10, 11, 12 and 13. The particular pressure responsive means Yillustrated is a fluid pressure responsive diaphragm and the particularpressure supply Z illustrated is a duct in communication with a sourceof fluid under pressure, for example, air under pressure, and said airpressure being subject to fluctuations in pressure.

In accordance with the invention the pressure responsive means Y isdirectly connected to the switch element of the switch X, namely, thecontacts 11 and 13, and the means Y or diaphragm involves a body 15 witha wall 16 defining a chamber 17 that is in open communication with thepressure supply Z. The body 15 supports a flexible and pressuresensitive membrane .18 that closes the chamber 17 and which membranecarries a contact mounting 19. In the particular case illustrated, thecontact mounting 19 is grounded to the membrane, in which case themembrane is made of conductive material or incorporates a ground to thebody 15. In the preferred form, the mounting 19 is an upstanding partthat projects from the membrane 18 and which has a transverselyextending member 20 that is in a plane normal to the axis of movement ofsaid diaphragm membrane 18. More specifically, the member 20 is a flatmetallic plate with the side facing away from the membrane forming thecontact 13. It will be apparent that pressure of fluid upon the membrane18 will move and position said membrane with consequent positioning ofthe member 20 presenting the contacts 11 and 13.

The switch X involves, generally, a housing A, guide means B, relativelymovable contact carriages C and D, a shiftable support E, a carriageadjustment means F, and a support adjustment means G. The said elementsof the invention, A through G, are constructed along the ex tended axis,or axis of movement, of the diaphragm membrane 18, the housing A beingprovided to support and enclose the other elements. The guide means B issupported within the housing A and is provided to shiftably carry thecarriages C and D and also the support E. The carriages C and D arecontact supporting elements that are adjustably positioned along theaxis of the structure and are provided for differential adjustment ofthe switch X. The support E carries or positions the carriage adjustmentmeans F that is provided for adjustably positioning the carriagesrelative to each other, and the support adjustment means G is providedfor adjustably positioning the said support E for range adjustment ofthe switch X.

The housing A that encloses the elements of the switch X is a framestructure adapted to be suitably mounted or installed as required andinvolves a case that supports and encloses the other elements and amounting for the case. The case 25 can be an open framework but ispreferably a closed case having a cylindrical wall with access openings26 as shown. The openings 26 can be closed by a cover 27 engaged overthe case and the ends 28 and 29 of the case are flat and normal to thecentral longitudinal axis thereof. A breather opening 27' can beprovided as required. In accordance with the particular form ofinvention illustrated, the end 28 is an open end and is provided with acoupling flange 31 connected to the body 15 of the diaphragm, while theend 29 is a closed end and is provided with a bottom 32. The mounting 30is shown engaged with and secured to the bottom 32 at the end 29 bymeans of fasteners 33, the mounting 30 being a plate-like element in theform of a dial 34 with indicia thereon calibrated for adjustment of themeans G later described. In practice, the dial 34 is recessed in whichcase the mounting 30 is disc-shaped, said dial 34 being in a planenormal to the axis of the cylindrical case 25.

The guide means B that is supported in the housing A to carry thecarriages D and C and the support E is provided to shiftably support thesaid carriages and the said support for movements longitudinally of theaxis of the structure. The guide means B can vary in detail ofconstruction but preferably involves a plurality of guideposts 35,preferably two spaced and parallel guideposts 35 that extendlongitudinally of the case 25 and parallel with the longitudinal axis ofsaid case. In practice, the two posts 35 are diametrically opposite theaxis of the structure and they are carried by and project from thebottom 32 of the case where they are provided with shoulders havingseated engagement with the case and threaded end portions receiving nutssecuring the posts in working position. The said posts are smoothcylindrical ele ments coextensive with each other and which terminate ator about the end 28 of the case 25.

The contact carriages C and D are essentially alike and are provided fordifferentially positioning the contacts 10 and 12 relative to eachother, and each is shiftably supported by the guide means B andindependently of each other. In practice, the carriages are in the formof flat plate-like bodies 36 and 46 with spaced parallel openings 37 and47 that slidable pass the posts 35, respectively. The two bodies 36 and46 are separated from each other longitudinally of the structure and areguided by the posts 35 to remain parallel with each other and they arecharacterized by central bores 38 and 48 for cooperation with theadjustment means F later described.

In accordance with the invention, the carriage C and body 36 thereofsupports and carries the contact 10 while the carriage D and body 46thereof supports and carries the contact 12. The contacts areessentially alike, the contact 10 being such as to engage with the abovedescribed contact 11 that faces toward the diaphragm membrane 18, thecontact 12 being such as to engage with the above described contact 13that faces away from the diaphragm membrane 18.

The contact 10 involves a contact arm 50 carried by an insulator 51,said insulator 51 being secured to the carriage C, while the contact 12involves a contact arm 60 carried by an insulator 61, said insulator 61being secured to the carriage D. The insulators 51 and 61 project fromtheir respective carriages and extend toward the membrane 18 and contactplate 20 carried thereby, and in a direction parallel with thelongitudinal axis of the structure. In the case of the insulator 51 thelongitudinal extent thereof is such as to place the contact arm 50 at orin the vicinity of the contact 11. In the case of the insulator 61 thelongitudinal extent thereof is such as to place the contact arm at or inthe vincinity of the contact 13. As clearly illustrated, the insulator51 is a post-shaped part that simply projects from the body 36 of thecarriage C while the insulator 61 is a post-shaped part that projectsfrom the body 46 of the carriage D and by or through the body 36 of thefirst mentioned carriage C. In carrying out the invention, the saidcarriage C is provided with an aperture 52 (see FIG. 5) that freelypasses the insulator 61 with substantial clearance.

The contacts 10 and 12 involving the arms 50 and 60 are preferablyspring contacts in which case the said arms 50 and 60 are resilientspring arms that are carried by the insulators 51 and 61 to beelectrically isolated from each other. As shown, the insulators 51 and61 are laterally olfset from the central axis of the structure and thespring arms 50 and 60 project inwardly, the arm 50 having a terminal endportion at the center of the struc' ture and forming the contact 10 andopposed to the contact 11, and the arm 60 having a terminal end portionat the center of the structure and forming the contact 12 and opposed tothe contact 13. As shown, the plate 20 is also at the center of thestructure intermediate the contacts 10 and 12. It will be apparent thatthe spacing of the contacts 10 and 12 from the contacts 11 and 13,respectively, will be determined by the positioning of the spacedcarriages C and D.

In the preferred form, the two posts 35 are stabilized at their outer orfree ends by means of a header 55 that engages with shoulders at theouter ends of said posts and which is secured thereto by means of nuts56. With the header 55 provided, as shown, the insulators 51 and 61project by or through the header 55, said header being provided withrecesses or openings therethrough that freely pass the insulators 51 and61 with substantial clearance (see FIG. 5).

The shiftable support E, that is provided to carry or position thecarriages C and D through the carriage adjustment means F laterdescribed, is similar to the carriages C and D and is shiftablysupported by the guide means B and independently of said other twocarriages. In practice, the support E is in the form of a flat platelikebody 66 with spaced parallel openings 67 that slidably pass the posts35. The body 66 is guided by the posts 35 to occur intermediate thebottom 32 of the case 25 and the said carriages C and D, and it ischaracterized by a central bore 68 for cooperation with the adjustmentmeans F later described.

The carriage adjustment means F that adjustably positions the carriagesC and D relative to each other for differential placement or positioningof the contacts and 12 is, in accordance with the invention, a screwadjustment means that shifts either one or both of the carriages toposition them, and the contacts carried thereby, in opposition to eachother. That is, either the carriage C or the carriage D can be moved,the other remaining still relative to the support E. It is preferred,however, that the two carriages C and D be simultaneously moved inopposite directions upon actuation of the means F, either to moveoppositely together or oppositely apart, as desired. As shown, theadjustment means F involves a stem 70 that is threadedly engaged in thebores 38 and 48, respectively, the stem being rotatably journaled in thebore 68 provided in the support E and the stem being accessible at thedial for manual adjustment.

The stem 70 is a shaft-like element with an enlarged threaded portion 71engaged in the bore 48 and with a reduced threaded portion 72 engaged inthe bore 38. Further, the stem has a shoulder 73 engaged with andpositioned by one side of the support body 66 and a collar 74 is securedthereto to engage with and be positioned by the other side of thesupport body 66. The threads at the portions 71 and 72 can bedifferential threads of different pitch, or they can be of the same aiidopposite pitch as indicated, and to the end that the carriages movetogether or apart when the stem 70 is rotated. As is indicated, the dial34 has an opening 75 freely passing the sleeve 80, said sleeve freelyprojecting through an opening 76 in the bot-tom 32 of the case 25.

The support adjustment means G that adjustably positions the support Efor range placement or positioning of the contacts 10 and 12, is, inaccordance with the invention, a screw adjustment means that shifts thesupport B so that the carriages C and D are shifted in unison. As shown,the adjustment means G involves a sleeve 80 that is threadedly engagedwith either the frame A or support E, and preferably threadedly engagedwith the support, in which case it is rotatably journaled in the frame Aand accessible at the dial 34 for manual adjustment. As shown, thesleeve 80 is coaxial with and is engaged over the stem 7 0 abovereferred to and the sleeve 80 is threaded onto a projecting portion ofthe body 66 of the support E. The stem has an enlarged internallythreaded portion 81 that engages with the said threaded projection ofthe body 66, the remainder of the sleeve freely passing the stem 70.Further, the sleeve 80 has a shoulder 83 engaged with and positioned byone side of the bottom 32 and a collar 84 is secured thereover to engagewith and be positioned by the other side of the bottom 32. It will beapparent that the support E is shifted longitudinally in one directionor the other depending upon the direction of rotation of the sleeve 80.

From the foregoing, and from a study of the drawings, it will beapparent that the structure disclosed can be readily assembled and thatit is rugged and durable. In order to eliminate freedom of movement orplay be tween the relatively movable carriages C and D, when they havebeen selectively positioner, I provide means to yieldingly urge saidcarriages oppositely. Preferably, I employ one or more simple compressedsprings 90 intermediate the carriages and which act to press thecarriages apart thereby applying pressure to the threaded engagement.Further, in order to eliminate freedom of movement or play between thecase A and support E, once the support has been selectively positioned,I provide means to yieldingly urge said support in one direction.Preferably I employ one or more simple compression springs 91intermediate the case A and support E to press them oppositely apartthereby applying pressure to the threaded engagement. It will be seenthat the said springs maintain tightness and freedom from play, eventhough wear takes place at the pants involved.

In order to selectively position the contacts 10 and 12 the means F andG are manually actuated, the sleeve being provided with a manuallyoperable control knob 95 with a pointer. 96, and said stem 70being'provided with an end configuration at 97 adapted to be engaged andoperated bya tool, such as, for example, a screw driver or the like. Aremovable plug 98 is provided in the knob 95 to gain access to the stem70 for operation thereof. Adjusting the switch both for differential andrange can be easily accomplished through rotation of the coaxialadjusting stem and sleeve fromoutside-of the case. Not only is theadjustment of micrometer magnitude, but

can be set to control an infinite number of ranges and/or differentialsof movement. Because of its ease of outside adjustment and low powerrequirements, it is possible to isolate or seal the structure within thecase A in order to protect it from any contaminatiing outsideatmosphere.

Having described only a typical preferred form-of my invention, I do notWish to be limited or restricted to the specific details herein setforth but I wish to reserve to myself any variations or modificationsthat may appear to those skilled in the art and which fall within thescope of the following claims.

Having described my invention, 1 claim:

1. A control switch having separate differential adjustment and rangeadjustment, and including, a carrier movable longitudinally in responseto the application of pressure thereto, opposite contact faces on thecarrier, a longitudinally disposed guide aligned with the longitudinalmovement of the carrier, a pair of longitudinally spaced and relativelyand independently movable carriages shiftably carried by said guide,opposed switch contacts supported by each carriage respectively andopposed to said contact faces on the carrier respectively, alongitudinally movable supportshiftably carried by said guide,differential adjustment means carried by the support and comprising amanually adjustable part engaged between and positioning the carriageslongitudinally relative to each other, and range adjustment meanscomprising a manually adjustable part positioning the supportlongitudinally.

2. A control switch having separate differential adjustment and rangeadjustment, and including, a carrier movable longitudinally in responseto the application of pressure thereto, opposite contact faces on thecarrier, a longitudinally disposed guide aligned with the longitudinalmovement of the carrier, a pair of longitudinally spaced and relativelyand independently movable carriages shiftably carried by said guide,opposed switch contacts supported by. each carriage respectively andopposed to said contact faces on the carrier respectively, alongitudinally movable support shiftably carried by said guide,differential adjustment means carried by the support and comprising amanually rotatable part engaged between and positioning the carriageslongitudinally relative to each other, and range adjustment meanscomprising a manually rotatable part positioning the supportlongitudinally.

3. A control switch having separate differential adjustment and rangeadjustment, and including, a housing, a carrier movable longitudinallyrelative to the housing in response to the application of pressurethereto, opposite contact faces on the carrier, a longitudinallydisposed guidepost carried in the housing in alignment with thelongitudinal movement of the carrier, a pair of longitudinally spacedand relatively and independently movable carriages shiftably carried onsaid guidepost, opposed switch contacts supported by each carriagerespectively and opposed to said contact faces on the carrierrespectively, a longitudinally movable support shiftably carried by saidguidepost, differential adjustment means comprising a part operable fromthe exterior of the housing and carried by the support and engagedbetween the carriages to adjustably position the carriageslongitudinally relative to each other and range adjustment meanscomprising a part operable from the exterior of the housing and engagedwith and positioning the support longitudinally of the housing.

4. A control switch having separate differential adjustment and rangeadjustment, and including, a housing, a carrier movable longitudinallyrelative to the housing in response to the application of pressurethereto, opposite contact faces on the carrier, a longitudinallydisposed guidepost carried in the housing in alignment with thelongitudinal movement of the carrier, a pair of longitudinally spacedand relatively and independently movable carriages shiftably carried onsaid guidepost, opposed switch contacts supported by each carriagerespectively and opposed to said contact faces on the carrierrespectively, a longitudinally movable support shiftably carried by theguidepost, differential adjustment means comprising a part rotatable inthe support and extending between and threadedly engaged 'in eachcarriage to position the carriages longitudinally relative to eachother, and range adjustment means comprising a part rotatably supportedin the housing and threadedly engaged in and positioning the supportlongitudinally of the housing.

5. A control switch having separate difierential adjustment and rangeadjustment, and including, a housing, a carrier movable longitudinallyrelative to the housing in response to the application of pressurethereto, opposite contact faces on the carrier, a longitudinallydisposed guide in alignment with the longitudinal movement of saidcarrier, a pair of longitudinally spaced and relatively andindependently movable carriages shiftably carried by said guide, opposedswitch contacts supported by each carriage respectively and opposed tosaid opposite contact faces on the carrier respectively, alongitudinally movable support shiftably carried by said guide,differential adjustment means comprising a differentially threaded partrotatably carried by the support and extending between and threadedlyengaged in the carriages and positioning the carriages longitudinallyrelative to each other, and range adjustment means comprising a partrotatably supported in the housing and threadedly engaged in andpositioning the support longitudinally of the housing.

6. A control switch having separate differential adjustment and rangeadjustment, and including, a housing, a carrier movable longitudinallyrelative to the housing in response to the application of pressurethereto, opposite contact faces on the carrier, a longitudinallydisposed guidepost carried in the housing in alignment with thelongitudinal movement of the carrier, a pair of longitudinally spacedand relatively and independently movable carriages shiftably carried onsaid guidepost, opposed switch contacts supported by each carriagerespectively and opposed to said contact faces on the carrierrespectively, a longitudinally movable support shiftably carried by theguidepost, differential adjustment means operable from the exterior ofthe housing and comprising a part rotatable in the support and extendingbetween and threadedly engaged in each carriage to position thecarriages longitudinally relative to each other, and range adjustmentmeans operable from the exterior of the housing and comprising a partrotatable in the housing and threadedly engaged in and positioning thesupport longitudinally of the housing.

7. A control switch having separate differential adjustment and rangeadjustment, and including, a housing, a carrier movable longitudinallyrelative to the housing in response to the application of pressurethereto, opposite contact faces on the carrier, a longitudinallydisposed guide aligned with the longitudinal movement of the carrier, apair of longitudinally spaced and relatively and independently movablecarriages shiftably carried by said guide, opposed switch contactssupported by each carriage respectively and opposed to said oppositecontact faces on the carrier respectively, a longitudinally movablesupport shiftably carried by said guide, difierential adjustment meansoperable from the exterior of the housing and comprising adifferentially threaded part rotatably carried by the support andextending between and threadedly engaged in and positioning thecarriages longitudinally relative to each other, and range adjustmentmeans operable from the exterior of the housing and comprising a partrotatable in the housingand threadedly engaged in and positioning thesupport longitudinally of the housing.

Harrington Feb. 15, 1927 Judson Dec. 4, 1956

1. A CONTROL SWITCH HAVING SEPARATE DIFFERENTIAL ADJUSTMENT AND RANGEADJUSTMENT, AND INCLUDING, A CARRIER MOVABLE LONGITUDINALLY IN RESPONSETO THE APPLICATION OF PRESSURE THERETO, OPPOSITE CONTACT FACES ON THECARRIER, A LONGITUDINALLY DISPOSED GUIDE ALIGNED WITH THE LONGITUDINALMOVEMENT OF THE CARRIER, A PAIR OF LONGITUDINALLY SPACED AND RELATIVELYAND INDEPENDENTLY MOVABLE CARRIAGES SHIFTABLY CARRIED BY SAID GUIDE,OPPOSED SWITCH CONTACTS SUPPORTED BY EACH CARRIAGE RESPECTIVELY ANDOPPOSED TO SAID CONTACT FACES ON THE CARRIER RESPECTIVELY, ALONGITUDINALLY MOVABLE SUPPORT SHIFTABLY CARRIED BY SAID GUIDE,DIFFERENTIAL ADJUSTMENT MEANS CARRIED BY THE SUPPORT AND COMPRISING AMANUALLY ADJUSTABLE PART ENGAGED BETWEEN AND POSITIONING THE CARRIAGESLONGITUDINALLY RELATIVE TO EACH OTHER, AND RANGE ADJUSTMENT MEANSCOMPRISING A MANUALLY ADJUSTABLE PART POSITIONING THE SUPPORTLONGITUDINALLY.